Starter engine

ABSTRACT

A self-sufficient system for assuring reliable starting of aircraft engines including a plurality of propellant actuated initiators located in parallel arrangement adjacent corresponding jet fuel combustors to lead and direct the products of combustion directly onto the turbine blades of the starter engine for setting the same into motion long enough to enable the jet fuel combustion to take over in the starter.

United States Patent 1 Larsen, deeeased et al..

[111 3,750,394 51 Aug. 7, W73

[ STARTER ENGINE [75] Inventors: Agnew E. Larsen, deceased, late of.lenkintown, Pa.; by William H. Larsen, executor, Doylestown; ManuelWeiustoelt, Philadelphia, both of Pa.

[73] Assignee: The United States oil America as represented by theSeeretary of the Army, Washington, DC.

[22] Filed: Jan. 4, 1972 [21] Appl. No.: 215,294

[52] US. Cl. 60/3914, 60/3937 [51] lint. Cl. F02c 7/26 {58] Field ofSearch ..60/39.14, 39.37

[56] 3 References Cited UNITED STATES PATENTS 3,280,556 10/1966 Durctinet al 60/39.l4

3,238,721 3/1966 Brandes et a1. 60/39. 14 2,982,095 5/1961 Campbell60/3914 2,895,295 7/1959 Carlson 60/39.]4 3,633,360 1/1972 Kelley60/3914 3,439,495 4/1969 Binsley et al. 60/39.]4 3,675,417 7/1972 Shum,.Ir 60/3914 Primary ExaminerCarlton R. Croyle Assistant Examiner-WarrenOlsen Attorney-Harry M. Saragovitz et al.

[5 7] ABSTRACT A self-sufficient system for assuring reliable startingof aircraft engines including a plurality of propellant actuatedinitiators located in parallel arrangement adjacent corresponding jetfuel combustors to lead and direct the products of combustion directlyonto the turbine blades of the starter engine for setting the same intomotion long enough to enable the jet fuel combustion to take over inthestarter.

1 Claim, 2 Drawing Figures STARTER ENGINE The invention described hereinmay be manufactured, used, and licensed by or for the Government forgovernmental purposes without the payment to us of any royalty thereon.

The invention relates to an engine starting system and moreparticularly, to a jet fuel starter for an aircraft engine. 1

A serious problem presently existing in aircraft engines is the chanceof power plant flame out" while in flight which may necessitate anabandonment of the aircraft by the pilot.

It is an object of the present invention to provide an aircraft enginesystem having an emergency re-start capability in the event of engineflame-out during flight.

A further object is to provide such an aircraft engine system having anindependent self-sufficient re-starting capability for normal operationof the starter engine.

These and other objects, advantages and features will become moreapparent from the following description and accompanying drawing inwhich:

FIG. l is a longitudinal sectional view of a starter engine embodyingthe principles of the invention.

FIG. 2 is a sectional view with certain parts omitted, taken along lines2-2 of FIG. 1.

The jet fuel starter engine system, shown generally at it) (FlG. ll),includes a casing ll having a funnel shaped air intake throat portion12. A compressor 13 is mounted on one end of the central longitudinallyextending shaft 14 adjacent a suitable pair of bevel gears thatinterconnect shaft 14 with shaft 115 of an appropriately mountedelectric starter generator 16 containing suitable ring and pinion drivemeans. Generator 16 normally functions to impart rotary motion tocompressor l3, its shaft M and primary turbine wheel 17 carried therebyand rotatable therewith. Air is thus drawn past the compressor 13 to mixwith the fire gases drawn from the circumferentially spaced combustorchambers 18 (FIGS. 1, 2), such that the comb'ustibly developed gaspressure will rotate or operate the main turbine blade 19 prior toexiting through exhaust passages 20. Connected to the main turbine 19 orits shaft 21 through a suitable gear reduction unit and torque convertor (not shown) is a power take-off gear or shaft 24 that isappropriately connected to an aircraft engine (not shown).

Corresponding cartridge initiators or gas generators 26 (FIGS. 1, 2) aresuitably mounted in a manifold construction 27 that is nested upon andbetween the combustors 118. The arrangement is such that pressure gasdeveloped by a selectively fired cartridge initiator will impinge uponand rotate the primary turbine blade 17 which starts or operatescompressor 13 prior to combustor gases being fired to operate the mainturbine blade 19, as described above. The ability to selectively firethese multiple cartridge initiators enables emergency re-starting of astalled or disabled engine, a feature which can be repeated by firinganother one or more of the initiators 26.

When it is desired to operate the starter engine by firing a cartridgeinitiator in place of the regularly functioning electric generator 16,the latter can be unloaded electrically by a pilot suitably switching toanother electrical circuit (not shown) which preferably would ready thecartridge initiators 26 for electrical firing thereof by a pilotcontrolled selective ignition switch (not shown), although it isconceivable that the initiators could be fired electrically ormechanically.

Air from outside the starter engine is drawn past the respective firedcartridge initiator 26 to augment the developed pressure gas forimpinging upon the primary turbine blade 17. Whereas air drawn by thecompressor 13 enters the rearward combustors l8 and fires the jet fuelthereof. Excess air augments the generated pressure gas to enter theturbine and operate the main blade 19. The residue gas continues in thedirection of the arrows toward exhaust ports 20.

We wish it to be understood that we do not desire to be limited to theexact details of construction shown and described for obviousmodifications will occur to a person skilled in the art.

We claim:

1. A jet fuel self-sufficient starter engine comprising,

a casing,

air intake means at one end of said casing,

a compressor mounted on one end of a shaft immediately inside saidintake means,

a primary turbine wheel mounted on the other end of said shaft,

a plurality of combustors mounted around said shaft,

a main turbine wheel adjacent said primary turbine wheel and actuated bygases developed in said combustors, and

a plurality of propellant actuated initiators in fluid communicationwith said primary turbine wheel, each initiator having a nozzle in fluidcommunication with and directed at said primary turbine wheel in such amanner so that the generated propellant gases from any of saidinitiators impinge directly upon the turbine wheel blades to rotate saidblades at a velocity sufficient to initiate normal operation of saidcompressor, combustors and turbines, each of said initiators beingmounted in a manifold, said manifold being nested upon and locatedbetween adjacent ones of said combustors.

i ll t I

1. A jet fuel self-sufficient starter engine comprising, a casing, airintake means at one end of said casing, a compressor mounted on one endof a shaft immediately inside said intake means, a primary turbine wheelmounted on the other end of said shaft, a plurality of combustorsmounted around said shaft, a main turbine wheel adjacent said primaryturbine wheel and actuated by gases developed in said combustors, and aplurality of propellant actuated initiators in fluid communication withsaid primary turbine wheel, each initiator having a nozzle in fluidcommunication with and directed at said primary turbine wheel in such amanner so that the generated propellant gases from any of saidinitiators impinge directly upon the turbine wheel blades to rotate saidblades at a velocity sufficient to initiate normal operation of saidcompressor, combustors and turbines, each of said initiators beingmounted in a manifold, said manifold being nested upon and locatedbetween adjacent ones of said combustors.